Anyone able to provide what needs to be change in the core to allow this?
I was able to allow it in the email field by changing the regex in email_helper.php but I am using zoo visitor and have email as username set and username is not allowing it.
I have read about every post on the matter out there but they are all for older versions of EE. I am running 2.8.
Please help, this might be a deal breaker for me at this point.